Nondiverging vortex pinning barriers at low current densities across the putative elastic vortex-glass–vortex-liquid transition in (formula presented) films

A detailed analysis of the electric field–current density (formula presented) characteristics of (formula presented) films across the putative thermally induced elastic vortex-glass–vortex-liquid transition predicted by the (formula presented) curve scaling reveals that the expected increase of the collective pinning barriers with decreasing J is cut off in the low-(formula presented) region, signaling a dissipation process which involves the plastic deformation of the vortex system. The temperature and magnetic field dependence of the pinning barriers at low J does not change across the scaling-predicted glass transition line. For the investigated magnetic field range (0.5–7 T), over a relatively large temperature interval, in (formula presented) films there appears a continuous crossover in a pinned plastic vortex assembly, rather than a thermally induced elastic vortex-glass–vortex-liquid transition.